Diet has been vastly overcomplicated lately. For the purposes of energy management, the effects of food on your body are so simple that I can explain them in a few short paragraphs.
All food is made of macronutrients, micronutrients, water, and indigestible material.
Macronutrient management is key to energy management. Like I said in the previous section, your diet, or more specially, your intake of different macronutrients, affects how energy is stored and expended.
In this section, I’ll introduce the three macronutrients–protein, fat, and carbohydrate–and I’ll explain how the body uses/stores them for energy. I’ll talk about how the body expends energy in the next section.
Protein is the simplest macronutrient in terms of weight management. It’s important for your body, but has little bearing on fat loss/gain.
Protein contains ~4 calories per gram. However, most that you eat is not used for energy. Instead, it’s used for building and repairing your body. For this reason, whenever I count calories, I ignore calories from protein. That is:
net calories = total calories – (grams of protein * 4)
This equation is is not entirely accurate if you eat extremely high amounts of protein. Excess protein can be converted into glucose (a carbohydrate) by the body. However, you’d have to eat a lot of protein for this to occur. In addition, it’s not an efficient process; some of the calories are lost in the conversion.
If you feel hungry and need to fill up on something, eat as much protein as you want. Just watch the amount of fat and carbs that comes with it because there are very few foods that are high protein, low carb, and low fat.
Unlike the other two macros, the body does not store excess protein.
Fat is the most misunderstood macronutrient. Know this: there is nothing inherently wrong with fat. You need it to live, and your body is more suited to use energy from fat than energy from carbs (more on that in the next section).
Fat contains ~9 calories per gram. As with protein, not all fat is used for energy. However, since fat is used for energy much more often, do not exclude any fat calories from net calories.
There are two huge misconceptions about fat that I’ll debunk:
1. Eating fat makes you fat.
This is an intuitive sounding fallacy; fat is in food and you have too much fat in your body, therefore you must be eating too much fat. It’s completely bogus and dangerous even.
The correct fact is that eating fat makes you fat if you’ve exceeded your TDEE or if your body is secreting insulin (see the note on insulin below).
2. Eating fat, especially saturated fat, will clog your arteries and lead to heart failure.
This site isn’t about health, so I won’t go into great detail, but you should know at least this:
The study that concluded that eating saturated fat leads to heart disease was doctored. In fact, there is evidence to show that eating more saturated fats and less monounsaturated and polyunsaturated fats protects you from heart disease.
As you know, your body can store as much fat as it needs in fat cells. Stores are basically unlimited. Like I mentioned before, it’s stored when you exceed your TDEE or if you’re secreting insulin.
Carbs are the most controversial macronutrient.
Unlike the other two, carbs are used exclusively for energy, but your body does not need them to function properly. Carbs contain ~4 calories per gram.
Something that most people don’t realize is that all carbohydrates are sugar. All of them. Separating sugar from the rest of the carbohydrates on nutrition labels is absolutely useless. Eating a baguette is no different than eating a bag of Skittles. One may raise your blood sugar more than another, but ultimately, your body treats them exactly the same.
When counting carbohydrates in your diet, you only need to consider net carbohydrates, since some carbs yield little to no energy. Here is a practical equation for net carbs:
Net carbohydrates = total carbs – carbs from fiber – carbs from sugar alcohols
Once again, this is not entirely accurate (some fiber can be digested by the body and sugar alcohols contain small amounts of calories), but it’s good enough for purposes of practical energy management.
Your body will store carbohydrates in the form of glycogen, a glucose derivative, in your muscles and liver where they can be accessed quickly.
There is a limited amount of carb storage available in your body. The exact amount depends on your body size. Once carb stores are full, the body can convert some excess into fat for further storage in a process known as “de-novo lipogenesis”, but it is a difficult and inefficient process, so it doesn’t happen often.
Carbohydrates are also responsible for water weight. For every gram of glycogen your body stores, you’ll also store 4 grams of water.
Note: Macros and Insulin
Insulin is a vital hormone with two purposes: it manages blood sugar levels and causes fat storage.
Carbohydrates and some proteins are insulinogenic, meaning that the body releases insulin when you eat those macros.
For the purposes of practical energy management, ignore the effects of protein consumption on insulin since it is small compared to the effects of carbs on insulin release.
When insulin is in your bloodstream, the body has a tendency to store incoming fat into fat cells. In addition, your body cannot access fat reserves at this time. (This is why it’s important to keep your carb intake low during periods when you’re trying to lose weight. More on that later.)
These are the things that pass through your digestive system. Fiber is the main example, although there are some fillers found in certain foods and medications that are also undigestible.
Undigestible material is not vital to your diet at all; you don’t need an ounce of fiber to survive or thrive.
(Fun fact: If you eliminate most or all indigestible material from your diet, you won’t waste as much of your life in the bathroom.)
Micronutrients, vitamins and minerals, are important for your body for countless reasons, but if you’re already eating fresh, natural, non-empty foods, you don’t have to supplement or make an effort to eat more fruits/vegetables/whatever people are telling you to eat.
Micronutrients do not affect weight loss or gain (unless you’re so micro-deficient that you have thyroid problems), so all that I’ll say is that you should eat foods rich in them. Primarily meats, vegetables, and small amounts of fruit (if you want).
Avoid processed foods because they’re so empty in terms of micronutrients that they are artificially fortified with vitamins and minerals to make them appealing.
If you’re interested in tracking calories, here is a practical equation for net calories:
net calories = (grams of fat * 9) + (grams of net carbohydrates * 4)
Next, I’ll discuss the effects of macronutrients on energy expenditure.